Judge Richard Bond told them: ‘Production of counterfeit notes undermines the whole economy of the country. Only lengthy custodial sentences can be justified.’

Amrit, 45, and Prem, 43, said they produced the fake £10 notes to save their ailing Birmingham business.

The siblings, of Walsall, gave each note its own serial number, ensuring they were only identified as fakes after reaching banks early in 2011.

They were caught along with Kumar, of West Bromwich, and Mahey, of Birmingham, after police analysed data stored by their print equipment. The Karras were also banned from serving as company directors by judge Bond.